The present invention relates to electronic component packaging, and more particularly, to an electronic component package specially adapted for surface mounting techniques.
For many years, electronic circuit boards have been fabricated by interconnecting a plurality of electronic components, both active and passive, on a planar printed circuit board. Typically this printed circuit board has comprised an Epoxy/fiberglass laminate substrate clad with a sheet of copper which as been etched to delineate the conduct paths. Holes were drilled through terminal portions of the conductive paths for receiving electronic component leads which were subsequently soldered thereto.
More recently, so-called surface mount technology has evolved to permit more efficient automatic mass production of circuit boards with higher component densities. With this approach, components are automatically placed at preselected locations on top of a printed circuit board so that their leads are registered with, and lie on top of corresponding solder paths. The printed circuit board is then processed by exposure to infrared or vapor phase soldering techniques to re-flow the solder and thereby establish a permanent electrical connection between the leads and their corresponding conductive paths on the printed circuit board.
Dual in-line chip carrier packages have existed for many years. The most common example is an integrated circuit which is bonded to a ceramic carrier and electrically connected to a lead frame providing opposite rows of parallel electrical leads. The integrated circuit and ceramic carrier are normally encased in a black, rectangular plastic housing from which the leads extend. Typically these dual in-line packages are mounted horizontally, i.e. with the leads extending co-planar with the printed circuit board. Such dual in-line packages have heretofore been attached to printed circuit boards by surface mounting techniques.
It would be desirable to provide a single-in-line package that could be vertically oriented to save space on the printed circuit board. However, due to the relatively high center of gravity, such devices may not be stable after placement upon the printed circuit board. This can lead to the component tipping over, or the leads pulling away from the solder pads, prior to solder re-flow. Any single in-line package intended to be vertically oriented should allow for automatic optical inspection of the final solder joints. Furthermore, in order to facilitate high volume manufacturing, any such package should be configured for ready handling by automated pick and place equipment.